Abstract

Outcropping strata of the Cerro Toro Formation at Sierra del Toro (Sarmiento Vista outcrop), southern chile, highlight the internal complexity associated with submarine channel deposits. The outcrop exposures consist of facies deposited in an elongate fan-channel complex, greater than 100 km (62 mi) long, that occupied the axis of the Magallanes foreland basin during the Late Cretaceous (Campanian). Paleocurrent data indicate that flow was dominated by southward-directed axial currents. Based on the distribution of multiple, large-scale, channelized depositional elements in the outcrop belt, the deposits at Sarmiento Vista are interpreted to represent one of numerous feeder channels that debouched into the channel complex (Figure 1). The entire channelform depositional element studied is <1 km (<0.6 mi) wide through the bottom part of the succession. However, a marked broadening of the channel is apparent at the top of the interval where the topmost beds extend over a lateral distance of at least 2.5 km (1.6 mi). The outcrop is oriented perpendicular to the paleochannel axis and exhibits 180 m (590 ft) of total relief over a lateral distance of approximately 250 m (820 ft). Fine-grained, out-of-channel deposits are mostly covered by vegetation and scree, limiting detailed interpretation of the channel margins.

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Tor H. Nilsen, a red-haired Scandinavian who stood more than six feet tall, died October 9, 2005, at his San Carlos, California, home. This was after a valiant five-year fight with melanoma cancer. He was 63. His ashes were scattered at his family plot in Norway in 2006.

He was born in New York City on November 29, 1941, to Mollie Abrahamson and Nils Marius Nilsen of Mandal, Norway, and was the first of their children to be born in the United States. After graduating from Brooklyn Tech, he earned his B.S. in geology from City College of New York in 1962. While there, his prowess on the basketball court impressed a scout from the New York Knicks, but Tor went on to graduate school and earned his M.S. and Ph.D. degrees in geology from the University of Wisconsin at Madison in 1964 and 1967, respectively. His M.S. thesis was a study of Precambrian metasedimentary deposits in the Lake Superior area, and his Ph.D. thesis was a study of Devonian alluvial-fan deposits of the Old Red Sandstone in western Norway.

Dr. Nilsen’s principal expertise was in depositional systems analysis, stratigraphic analysis, and the relationships among tectonics, eustasy, and sedimentation. He began his industry career in 1967 as a research geologist with the Shell Development Company in Houston, Texas, and Ventura, California, where he worked on the tectonics and sedimentation of Tertiary shelf systems of coastal California. He subsequently spent two years with the U.S. Army Corps of Engineers as the Military